Ideas for Making Planters for Around Trees

A tree with lots of space around it allows for better spacing of plants underneath.

A planter adds color and visual interest to the area around the base of a tree, but precautions are necessary to allow both the tree and the plants to thrive. Excessive damage or interference with the root system of the tree threatens its growth. Thoughtful selection and planning for the plants, materials and design result in an attractive and functional flowerbed.

Size

You need an idea of how large to make the planting area to start this project. Planting closely to the tree trunk increases the risk of injury to the roots. Your watering of the plants may inadvertently create too much moisture for the tree. Leave several feet between the tree trunk and the flowers you plant around it. The University of California Master Gardeners San Luis Obispo recommends leaving a no-planting zone of 6 feet around the trunk of oak trees. This recommendation requires a large planter area around the tree. Mark the desired size of the planting zone and take measurements to help decide on the specific area.

Design

Round planters around trees replicate the roundness of the tree trunk. For contrast, choose a square design for the planting area. Square planting areas are easier to build because you can don't have to create curves with the selected border material. Terracing or building multiple sections gives you more design options. You might build a small inner section defined by a border with another larger section surrounding it. For the best growing environment, work with the natural grade of the soil surrounding the tree. If the soil slopes down away from the tree, make a terraced planter with a higher inner planting section and a second lower planting section surrounding the first. Avoid building up extra soil around the trunk of the tree.

Border

A number of landscaping border materials work as the edging for a planter around a tree. Pavers, brick and stones give you flexibility in the height of the border. These materials also make curves easier because of the small size of each piece. A row of pavers or bricks installed at ground level allows you to mow around the planter easily. Landscape timbers work well to create straight edges for the planter border. Simple plastic or metal landscape edging provides a lightweight option for defining the planter edges. Gather information on the size and weight of the selected border and how it may compact the soil to avoid harming the tree. Compacting the soil reduces oxygen available to the roots, sometimes affecting the growth.

Plants

Plants grown under a tree receive little direct sunlight and rain due to the tree's canopy. Choose plants that grow well under these conditions and are also suited for your specific climate. Plant species native to the area are better adjusted to the conditions and are more resistant to potential pests. Choose perennials so you only need to disturb the soil the first year to initially plant the flowers. Smaller plants also minimize the amount you need to dig and result in less impact on the tree roots. Plants with a reasonable chance of flourishing in the planter under the tree include hummingbird sage, California fuchsia, bush poppy, yarrow or creeping sage.